Forests of genetically altered trees and other plants could sequester several billion tons of carbon from the atmosphere each year and so help ameliorate global warming, according to estimates published in the October issue of BioScience.

Hardly surprising, then, that people interested in reducing emissions are looking more and more at agriculture. Essentially, the need to produce more on the same land area together with the recent drop-off in the rate of yield increase from conventional breeding make it imperative to use tools such as GM to increase overall harvests.

Producing more means leaving more forest intact, which is a major objective of climate change policy. Use of herbicide-tolerant plants encourages the adoption of no-till farming, which reduces the loss of soil carbon. No-till agriculture and pest-resistant crops reduces the number of tractor passes needed and hence fuel consumption and so saves yet more carbon dioxide emissions. Reduced ploughing also helps to retain soil moisture and build up organic matter. Drought-resistant and stress-tolerant plants are beginning to emerge from the R&D pipeline. These will increase overall yields and enable adaptation of crops to the more extreme climate predicted for some regions.

Faster development of the promising field of cellulosic biofuels – the renewable energy produced from grasses and trees – is being significantly hampered by a “deep and thorny regulatory thicket” that makes almost impossible the use of advanced gene modification methods, researchers say.